Custom civil drainage products

What it is

Every civil project has drainage items that no standard range covers: a grate for a skewed pit, a cover for an irregular opening, a screen across a culvert, or a ladder into a deep chamber. World Steel makes these to drawing, using the same people, procedures and quality records as our structural steel. Custom items can be produced alongside standard steel drainage grates, pit covers and trench covers, so a project receives one coordinated delivery.

We work either from the engineer's design or from a sketch and performance brief, in which case World Steel prepares shop drawings and checks the item for the required load class before fabrication.

Custom work is most valuable where the alternative is site fabrication. A grate cut and welded on site to suit an awkward opening is rarely galvanised properly, seldom checked for load and difficult to replace. Made in the factory, the same item is dimensioned from the survey or model, welded to a qualified procedure, fully galvanised and marked, so a replacement can be ordered from the drawing years later. Where an item will repeat across a project, we make a first article for approval before batch production.

Types and options

Design and compliance

Trafficable grates and covers are designed or checked for the class set by the designer – AS 3996-2019 classes A to G in Australia, EN 124 classes A15 to F900 in Europe, or AASHTO H-20 / HS-20 or HL-93 in the US. Trash racks and screens are checked for the hydraulic and debris loads given in the design brief; World Steel does not set these loads and will ask for them where they are missing. Where a standard requires a physical type test, test evidence is product-specific and must be agreed with the client before ordering.

Pit ladders follow the rung spacing, width and fall-protection rules of the governing code – AS 1657, OSHA 1910.23 or EN ISO 14122-4 – as described on our fixed ladders page. Cast-in frames and anchors are detailed to the concrete interface, as for embed plates and cast-in items.

Fabrication and finishing at World Steel

Plate, bar and sections are cut on CNC plasma and saws, drilled and welded to qualified procedures under ISO 3834-2 and AS/NZS 5131. Hinges and locking details are trial-fitted before coating, and every item is checked against the shop drawing. Items are hot-dip galvanised by qualified galvanisers to AS/NZS 4680, EN ISO 1461 or ASTM A123, with vent and drain holes detailed in advance so that the zinc reaches every surface.

Custom items are marked to the drawing, banded or crated, and packed with the structural steel for export shipping.

Installation and specifying

• Supply drawings or sketches with the opening dimensions, levels and concrete details.
• State the load class, or the hydraulic and debris loads for screens and racks.
• Say which items must hinge, lock or be removable, and how maintenance staff will lift them.
• On site, set frames level, bed them fully, then fit grates and screens and check hinges and locks.